摘要
采用大涡模拟与声类比的方法研究了周期性凸起结构对圆柱绕流流场及声场的影响。以30 mm直径的圆柱为研究对象,设计的凸起结构周期为1/3直径,凸起结构展向厚度为1/10直径,同时设计了42 mm与48 mm两种不同直径的凸起结构。模拟雷诺数123100下基准圆柱与两种带周期性凸起结构圆柱的流场与声场,详细分析了凸起结构对气动力系数的影响,同时分析了凸起结构对圆柱绕流涡脱落噪声的影响。研究发现,直径更大的凸起结构降低噪声的效果更显著,25000 Hz以下的总声压级降低高达19 dB;同时凸起结构也能够降低升力系数波动及阻力系数的均值。进一步研究表明,周期性凸起结构的降噪机理在于,周期性凸起结构破坏了圆柱绕流在展向上脱落涡的连续性。
Large eddy simulation and acoustic analogy are used to study the effect of the periodic convex structure on the flow and sound fields of a circular cylinder.Taking a cylinder with a diameter of 30 mm as the research object,the period of the convex structure is a diameter of 1/3,and the spanwise thickness of the convex structure is a diameter of 1/10.Two kinds of convex structures with the diameters of 42 mm and 48 mm are designed.The flow and sound fields of the reference cylinder and two kinds of cylinders with periodic convex structures at a Reynolds number of 123100 are simulated.The influence of the convex structure on the aerodynamic coefficient and the vortex shedding noise of the cylinder are analyzed in detail.It is found that the larger diameter of the convex structure can reduce noise around the cylinder more significantly,the total sound pressure level at below 25000 Hz can be reduced by up to 19 dB;at the same time,the convex structure can also reduce the fluctuation of the lift coefficient and the mean value of drag coefficient.Further research shows that the noise reduction mechanism of periodic convex structure lies in that the periodic convex structure destroys the continuity of shedding vortex in spanwise direction.
作者
王俊娇
冯和英
仝帆
王勇
WANG Junjiao;FENG Heying;TONG Fan;WANG Yong(Hunan Key Laboratory of Mechanical Equipment Health Maintenance,Hunan University of Science and Technology,Xiangtan 411201,Hu′nan,China;Key Laboratory of Aerodynamic Noise Control,China Aerodynamics Research and Development Center,Mianyang 621000,Sichuan,China)
出处
《机械科学与技术》
CSCD
北大核心
2022年第8期1306-1312,共7页
Mechanical Science and Technology for Aerospace Engineering
基金
国家自然科学基金项目(51875194,1160229)
湖南省教育厅优秀青年基金项目(20B226)。
关键词
圆柱绕流
凸起结构
气动力系数
降噪机理
flow around cylinder
convex structure
aerodynamic coefficient
noise reduction mechanism
